1. Field of the Invention
The present invention relates to cooling devices and processes and, ore particularly, to the cooling of subjects in order to produce such physiologic conditions as comfort or hypothermia.
2. The Prior Art
Prior proposals for producing physiologic cooling by radiant heat exchange have had restricted application. In one prior proposal (U.S. Pat. No. 2,651,503, Sept. 8, 1953, C. A. Mills, System of Radiant Heat Exchanging), interior walls of a room have reflective surfaces which tend to direct infrared radiation to a heat sink with limited intermediate absorption and emission. This system is such that multiple reflections at the walls tend to result in intermediate absorption and emission even if it were possible to maintain high reflectivity of the walls under practical conditions. In another prior proposal (U.S. Pat. No. 3,282,267, Nov. 1, 1966, W. Eidus, Thermoelectric Hypothermia Instrument), cold panels are spaced about the patient in order to establish radiative heat exchange. This system is such that the panels must be unduly large or unduly close to the subject if appreciable radiation exchange is to be achieved. In a more recent proposal (U.S. Pat. No. 4,155,226, May 22, 1979, G. Altman, Infrared Cooler For Restricted Regions), intensified cooling of a restricted region is achieved by utilizing certain principles of geometrical optics to relate the subject region to a large infrared condenser and a small heat sink. The present invention takes advantage of certain mechanical-thermal-optical relationships to provide an infrared radiation cooler that is capable of operating effectively throughout a desired region, without being unduly close to the subject, to produce such physiologic conditions as comfort or hypothermia.